﻿<blockquote class="extDef">NOTE&nbsp; Definition according to ISO/CD 10303-42:1992<br>
This function returns the basis surface for a curve as a a set of surfaces. For a curve which is not a curve on surface an empty set is returned.</blockquote>

<blockquote class="note">NOTE&nbsp; Function adapted from <strong>get_basis_surface</strong> defined in ISO 10303-42.</blockquote>
<blockquote class="history">HISTORY&nbsp; New function in IFC1.5</blockquote>